Petroleum refining apparatus



April 5, 1932.

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F. A. MILLI'FF ET Al.

PETROLEUM REFINING Original Filed Jan.

APPARATUS '7 Sheets-Sheet. 2

Z55 25a (D Q and m NUI/ff,

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April 5, 1932. F. A. MILLIFF ET AL 1,852,184

PETROLEUM REFINING APPARATUS Originl Filed Jan. l1, 1926 7 Sheets-Sheet5 liz Ao/wey.

April 5, 1932. F. A. MlLLlFF ET AL 1,852,184

PETROLEUM REFINING APPARATUS Original Filed Jan. 1l. 1926 7 Sheets-Sheet4 I l l l l l l l I l April 5, 1932. 1,852,184

F. A. MILLIFF ET AL PETROLEUM REFINING APPARATUS Original Filed Jan. 11.1926 7 Sheets-Sheet 5 April 5, 1932. v F. A. MILLIFF ET AL 1,352,184

PETROLEUM REFINING APPARATUS Original Fled Jan. 11. 1926 7 Sheets-Sheet6 orwey.

Apil 5, 1932.

1M /pjyfj F, A. MILLIFF ET AL PETROLEUM REFINING APPARATUS OriginalFiled Jan. l1. 1926 l 7j@ Z0 7 Sheets-Sheet '7 Patented Apr. 5, 1932.eineres Parent;

erica PETRLEUM RLEIFILCIIWG APPARATUS Appleatonvlefl January 11, i526,Serial No. 80,583. ReneWed`Dece1nber 27, 1928.

Our invention relates to petroleum'reiining apparatus and includes anovel form of fractionating tower.

In yone of the'more modern methods of refining petroleum oil, the crudeoil is heated in a pipe still up to about 500 F. The hot crude eil isthen conducted from the still to a vaporizer in which the more volatilehydron carbons are separated from the residuum as vapors. The mixture ofthese vapors so separatedis then conducted through adephlegmator whichcools the vapor mixture to a point where a certain group of the lessvolatile hydrocarbon lvapors condense and are removed from the vaporymixture. Theremainder of the vapor mixtureV goes tol a seconddephlegmator, where it is further cooled', and another group of theremaining hydro-l carbon vapors are condensed Aand removed from themixture. In the same manner the remainder of the vapor mixture isprogres,- sively cooled and condensed in furthery de'- phlegmators. Inthe present practicel a total of six dephlegmators is generally used,the vapor mixture which leaves vthe last dephlegmator being completelycondensed in a condenser. Eachoi' the groups of hydrocarbons which aseries of dephlegmators thus separates out from the vapor mixture maycomprise a commercial'produ'caor itmay be further refined. In orderoftheirboiling points, and, hence, in the order in which they arecondensed from the vapor mixture, these productsarecommonly termedgasoil, stove oil, several grades of distillate,ker0sene and gasoline.

Inasmuch as the same relinery mayiind itA necessary to purchase crudepetroleum, com.- posed of various proportions of Ahydrocar- Vbons,oitis'very desirablethatvin a refining process such as just described,complete control of the temperatures of condensation may be possible ineach stage of reduction of the vapor mixture into liquidhydrocarbonprod` ucts. It is alsodesirable to effect anecono-` my; in first cost ofconstructionV and'm the cost of operation of such a fractional distil?lation apparatus.

It is an obiect of our invention, therefore,

-to oro. .de a sinele fractionatino tower which l c C Yvolatile thanthose desired in the takes the place of the several dephlegmators andaccomplishes a separation of the several hydrocarbon. productsenumerated above from a mixture of their vapors.

It is also an object of our invention to provide in such a ractionatingtower a series of vapor condensing sections, the temperature of each ci'which is controllable vso that as the vapor mixture passes through it apredetermined'group of hydrocarbonsis con-'g densed therein.

Itis another object of our invention to provide in such a ra'ctionatingtower a re-boiler associated vwith each vapor condensingsection inwhichthe condensate fromy that section is re-.boiled to drive oil' anyhydrocarbons condensed in that section which are more product to heremoved therein. n y It is a still` turtherob-ject of our invention toprovide in saidvapor ,condensing sections novel condensatepans havingvaporizer passageways therein and caps for downwardly detlecting thevapor rising through these passageways, so that when condensate standsat a certain level in said pans the vapor will be forced kto bubblethrough the condensate in order to escape upwardly.

Ano-ther object of our invention is to provide means for equallydistributingthe vapor through the condensate along the Whole length ofthese caps on each side thereof.

Still another object is to provide means for\cleter1niningthe level-ofcondensate in each pan,.and hencefthe depth below the sur-' tace of thecondensate at which the va-porsis released. i A further object ofourfinvention isto provide means for conductingthe overflowl cicondensatefromeach pan to the onenext below it anda novel and eiiicientmeans of intro. ducinga liquid hydrocarbon retluxfintofth'e condensateso that it will be thoroughly mixed, v therewith as itenters the lowerpan. y

Anotherobjectds to provide the re-boilers with heat exchange elementswhic-hare supplied through piping with a heating` medium, such as hotresidum, in such a manner thatf these heat exchangers may communicateinparallel fashion between the hot .residuumY supply and cool residuumreturn lines, or else they may be connected together so that all theresiduum passes into the lower heat exchanger and from it to the onenext above it, and so on up in series to the uppermost heat exchangerwhich has outlet connection with the cool residuum return lines.

Yet anotherobject of our invention is to .provide a novel condensate tapfrom each reboiler whereby the condensate is drawn from a lower level ofthe re-boile'r` and yet whereby the surface of the condensate ismaintained at a predetermined level in the re-boiler.

It is a further object to provide a re-boiler for each condensingsection in which the condensate from that section may be treated bymeans for applying dry heat thereto or by means for releasing steamtherein.

Another object of our invention is to provide means for cooling allofthe re-boilers when a drop in temperature becomes necessary.r A Otherobjects and advantages of our invention will be made apparent in thefollowing specification and in the,accompanyingdrawings, in which YFig.-1 is a diagrammatic view showing our fractionatin tower employed inaV typical apparatus for refining petroleum.

Fig. 2 is a fragmentaryelevational view of our fractionating tower takenin the direction of the arrow 2 in Fig. 3.

Fig. 3 is a fragmentary elevational view o-f our fractionating towertaken in the direction of the arrow 3 in Fig. 2.

Fig. 4 is a fragmentary vertical sectional view taken on the line 4-4 ofFig. 3.

Fig. 5 is a plan view of one of the condensing section pans of ourinvention with the caps partially broken away to show the riser openingsin the pan.

Fig. 6 is a vertical :sectional view Vtaken on the line 6 6 of Fig. 5and showing a pan' condensate discharge pipe with a refiux dischargepipe centrally disposed therein.

- Fig. 7 is a fragmentary vertical sectional View taken on the line 7-7of Fig. 5 and showing a' pan condensate collector pipe.

Fig.- 8 is a fragmentaryvertical sectional view taken on 4the line 8-8ofFig. 5 and showing one pan riser cap in end elevation and another intransverse section.

Fig. 9 is a fragmentary vertical sectional View taken on the line 9-,9ofFig. 5.

Fig. y10 is a'plan View of one of the re-boiler sections of ourfractionating tower.

Fig. l11 is a vertical sectional view taken on the line 11-11 of Fig.10.

n Fig. 12l is an enlarged fragmentary View of the left hand portion ofFig. 11.

' Fig. 13 is a vertical sectional Viewv of a novel ycentrifuge which isassociated with the:

vaporizer of the refining apparatus shownin Fig. 1.

Fig. 14 is a horizontal sectional View taken .on the line 14-14 of Fig.13.

apparatus for refining petroleum shown in Fig. 1 isa continuous pipestill process. This processhas a pressure pump 10 which draws crudepetroleum from the crude storage tank 11 and pumps it through a pipe 12to the pri- `mary heatV exchangers 13 from which it returns through apipe 14 to thev secondary heat exchanger-s 15, from which it is led by apipe 16 to a water separator 17, from which a pipe 18 ,conducts thecrude oil to the pipe still 25. A gas or oil burner'26 provides fire toheat the stillpipes 28, through which the crude oil-circulates vand fromwhich the oil is conducted through a pipe 30 at a tem,- perature ofabout 500 F., when treating a certain grade of oil chosen as an example,to a vaporizer 31. In the vaporizer 31 the hydrocarbons with boilingpoints below 500o F. separate out from the-residuurn in the Vform ofvapor-s. The residuum is still very hotl and is conducted from the,bottom of the vaporizer31-.through the pipe 32 to the secondary heatexchangersv 15, where it heats the charging crude and is cooled thereby,then passing on through a pipe 33 to a pipe 34 which leads to airesiduumstorage (not shown).

The mixture of vapors separated from the residuum, which are condensableat diiferent temperatures, pass from the vaporizer 31 through a vaporline 35 to a centrifuge 36.

loo

In this centrifuge entrained particles of liquid are removed from thevapor in they manner to be ldescribed later, and are returned to thevaporizer 31 through a pipe`37. '.lhevapor passes from the centrifuge 36through a vapor lin-e 38 which connects with a lower fractionating unit40 of the fractionating tower generally designated as 41.

The fractionating tower 41 in the embodiment shown has a Vertical shellformed by stacking a number of shell sections of the lsame cross sectionone upon the other. These shell sections are of two kinds, viz.condenser sections and re-boiler sections, each of the, former havingone of `the latter disposed immediately beneath it and in communicationtherewith to form aA fractionating unit. Stacked upon the bottomfractonating unit 4() and extending vertically upward therefrom arefractionating units 52, 53, 54, 55, 56 and 57, all Vof which areidentical in construction. Y The bottom fractionating unit 40, asillustrated in Figs. 2, 3 and 4, is composedofl a rvapor' vestibulecondensing section 60 and a tower base re-boiler section 61.

The section 60 has a shell 62 of rectangular horizontal section, whichis open at the upper tom of the'pipe and lower ends where attachingflanges and 66 respectively are formed uponthe shell 62. i A vapor inletopening 67 is formed in the medial portion of a wall 68 of the shell 62and the lower end of the vapor line 38 is secured againstthe wall ,68 bya flange 69 so that the vapor. line 38 communicates through th-e hole 67with a vestibule chamber 70 provided in the middle portion. of thesection 60. Fitted into th-e shell 62 just above the charnf ber 70 andwelded to the shell is ay vapor distributor plate 72. This plate isprovided with vapor distributing holes7 3 of an aggregate cross sectionequal to that ot the vapor inlet opening 67, andruniformly distributedover thesurface of. the plate 72.

A Icondensing panA has a floor plate 76 which is formed to tit theinside of the shell 62 and is welded therein in horizontal positioninedially between the distributor plate 72 and the upper end of thesection 60.

Referring to Figs. 4, 5, 8 and 9 for a detailed description of the pan75, six parallel vapor riser openings 77are formed in the pan floor 76and have walls7 8 rising upwardly along their edges to a uniform height.

A cap rests down over each riser openig77 outside the walls 78 upon thefloor 76. Each cap 80 has a ceiling 81, side plates 82 bent downwardlytherefrom, and end plates 83 closing the end openings. A cavity thusformed in tie cap 80 which opens at the lower edge of the side and endValls 82 and 83. Spacing studs formed on the outside oithe1walls78 spacethe cap 80 a distance from these walls. Notches 91 are formed in thelower edges oi cap side and end walls 82-and 83, the apeXes of which areall on a given level. An angle iron 92 is welded to the outer face ofcap walls 82 and 83 so as theicondensing pan 75 is provided with aninletor condensate discharge pipei94 andan outlet or condensatecollector pipe 95 which are projected hrough holes iorn'ied in the wallsof the shell 62 and wel-ded to these walls so that these two pipes aredisposed parallel to and a small distance from the floor 76 at oppositeends ot' the yparallel riser opening caps 80. Holes 96 are formedalongthe bot- 95 to allow liquid to pass thereinfrom the pan 75. j

Referring to Figs. 6, 7 and 9, the inlet and outlet pipes 94 and 95project outwardly at one end bevondl the wall of the'shell. and

- are threaded to receive a `cap 97 and ajoint flange 98 respectively.Attached to the iiange 98 is au adjustable weir 99 having a housing100and a rotor 101 having a weir opening 102 formed therein. The rotor101 is rotatably seated `in thehousing. 160 so .that

liquid may yflow through the valve99 only by passing through the Weiropening 102. The rotor 101 may be rotated manually to control theelevation or' the weir opening 1021l and, hence, the level which theliquid mustattain in the pipe y95 before it will iiow v through theopening 102 by. gravity.- vThe 'novel features of this adjustable weirare fully'shown, describedy and claimed in our United States LettersPatent issued March8, 1927, No. 1,626,164, andv reference may be had tothat thereon. 'j

The other end of the outlet pipe 95 is closed by a welded head 105, asshown in Figs. 6 and 9, and theother end of the inlet pipe 94 is closedby a welded head 106. Disposed through a hole in the head 106 and weldedto the head so that it projects centrally into the inlet pipe 94 is areflux-inlet pipe 107. ln Figs. 6 and 9 openings 110 are shown providedin the inlet pipe 94 along its top side and openings 111 are provided inthe pipe 107` toone lside of the top side thereof so as to be outofregistry with the holes 110. The purpose oi providing the holes 110Aand the holes 111 out of alignment with each other' will be describedlater.

rThecor'idensingpan 7 5 with the inlet and outlet condensate pip-es 94and 95 and the reflui; inlet pipe 107 comprises a condensing panassembly 112. y

identical in structure and manner of mounting with the assembly 112, andmountedone above the other in the shell 62 between the lower end thereofand the medial vvestibule chamber 70 are condensing pan assemblies 115and 116. Y

As indicated by dotted lines in Fig.f6, a pipe joint 'flange 120 isscrewed uponl each of the condensate dischargepipes 94 of the panassemblies 115 and ,116 and as shown in Fig. 2 the flanges 120 have gastrap elbows patent for further information- 121 and 122 joined theretoby end flanges 123 thereof.

flanges connects adjustable Weir housing 100 with the elbow 121 whichcommunicates with the condensate inlet pipe 94 of the pan assembly 115.The condensateoutlet pipe` 95 of thepan assembly 115 has an adjustableweir 126 which is connected by a pipe 127 to the elbow 122 whichcommunicates with the condensate inlet pipe 94 of the pan assembly 116.The outlet pipe 95 of the pan assembly 116 has a weir valve 128.

rlhe re-boiler section 61 has a shell 130 of identical cross sectionwith the she-ll 62 and is disposed beneaththe shellv 62 in alignment andin contact with it. A flange 131 provided at the .upper end. of theshell is suitably secured to the flange 66 to form a gas-tightjointbetween the shells 130and 62.. A flange 132 provided at the lower end.of the shell 130 is secured` to a base plate 133. A

,into a circuitouspassageway beginning and ending at the corners 140 and141 respectively of the shell 130.

Opening into the shell lat its corner 140, as shown ink F ig. 10, is aninlet pipe 142 and opening from the shell 130 at its corner 141is anoutlet pipe 145.

The inlet pipe 142 is connected through a gas trap elbow 146 and astandard 90o elbow 147 is Connected to the adjustable weir 128.

Tubes 149 pass through holes in the ends 138 and 139, as shown in Figs.11 and 12, so as to form a dry heating element 150 in each of the aisles151 formed by the baffle walls 137. These tubes 149 are rolled into agas-tight lit in the shell ends 138 and 139, and project outwardly ashort distance therefrom, wherethey pass into and are rolled to fittightly holes provided in inlet and outlet header boxesY 155 and 156.These header boxes 155and 156 have face plates 157 secured on the outerends thereof which may be removed to provide access to the tubes 149 forcleaning. An inlet pipe 160 is provided in the header box 155 and anoutlet pipe 161 is provided in the box 156.

, A collar 165, as shown in Fig. 12, is provided in the shell end 138opposite each of the aisles 151 and just above the floor 135. Aperforated steam outlet pipe 166 passes through the collar and extendsinto the chamber 136 almost to the opposite( end wall 139. The inner endof each pipe has a cap 167 and the outer end has a steam valve 168 whichconnects througha nipple 169 to a steam manifold 170.

description of the unit'52 will suflice for all of these unitsv whichare stacked consecutively upon each other as` shown in Fig. 1, above theunit 40.

' The fractionating unit 52, as shown in Fig. 4, comprises a condensingsection and a re-boiler section 181. The re-boiler section 181 isidentical to the re-boiler section 61 with the pan assembly 112and-mounted, as shown inv Fig. 4, in the same manner', one below theother. j

As shown in Figs. 3 and 4, the pan assemblies 191 to 196 have outletoverflow adjustable weirs 201 to 206 respectively. The pan assemblies192 to 196 have inlet gas trap elbows 212 to 216 respectively.

A pipe 222 connects the overflow weir 201 to the inlet elbow'212. nSimilarly, the overflow weirs 202 to 205 are connected by pipes 223 to226 respectively to inlet elbows 213 to 216 respectively.

The condensate inlet pipe 9401i the upper pan assembly 191 has a cap 230similar to the is secured tothe lower flange 66 ofthe condensing section180to form a gas-tight joint between these sections. y

ln a similar manner all pairs of'adjacent ends of the condensing andre-boiler sections of the fractionating units stacked upon each otherabove the unit 52 are joined together by flanges to form gas-tightjoints theref between.

Y Resting upon the upper end of the top fractionating unit 57 is a towercap 200. A flange 207 formed upon the cap 200 is secured to the upperflange 65 of the unit 57 and `forms a gas-tight union between the cap200 and the unit 57.

Referring again to Fig. 1, a vapor line 208 is provided to lead from thetop of the tower cap 200 to a gasoline condenser 209. A con- Thefractionating units 52, 53, 54, 55, 56V and 57 being identical instructure, a detailed densate rundown line 209a leads from the bottom ofthe condenser 209 to a storage tank A boiler 211 generates steam whichis conducted througha steam pipe 217 to each of the re-boiler steammanifolds 170. Likewise, a steam vlin-e 218 leads from the pipe 217tothe vaporizer 31 which, as diagrammatically illustrated, is the novelvaporizer shown, described and claimed in our United States Letters`Patent, issued October 11,1927, No. 1,644,937, to which reference may behad if further information regarding it is desired.

It is desirable that the temperature of the re-boilers be controlledover quitea large range. Means are therefore provided for supplying aheat exchanging medium to the header boxes 155 of thevarious'fractionating unitre-boilers and running the medium away fromthe header boxes 156, thus causing a flow of the medium through thetubes 149. The intake of a residuum pumpA 220 is controlledr by valves221: and 221a which communicate respectively wi lh the hot residuum line32 a d with a line 223a leading to the crude oil storage tank 11. Theadjustment ofthe valves 221 and 221a determinesA whether the heatexchanging medium drawn into the pump 220 will be het .residuuim coolcrude oil or a mixture oit .residuum and crude. From the pump 220 anoutlet pipe 225a communicates with a kstandpipe'generally desigsshowirin Fig. 3, this pipe 226m is builtup. Starting/at the bottom, thepartsas far asfragmentarily shown, comprise a T fitting 2303, a shut-olivalve 231, a pipe 232i, a tourway Fitting 233, a valve 234, a pipe 235,a fourway fitting 236 and a 'valve 237.

The T fitting 230a communicates through. a pipe 246, a'regulating valve241 andan Vel bow 242 with the inlet residuum header box an elbow 300with the outlet residuum headerV box 310 of the re-bo'iler section 311of the upnicates lon 155 ot thel lowermost re-boiler 61.Y The tour'- theright hand side through a pipeV 260, an

elbow 261, and a valve 262'with the inlet header box 263 of there-boiler 264 of the tractionating unit 53. i'

vThe fitting 236 communicates on the left hand side through a pipe 270,anelbow 271,y

a pipe 272, an elbow 273, a pipe 274, a valve 275`and a T iitting 276withthe residuum outlet header boX'27'7 of the re-boil'er section181. Abuilt-up residuum return'line 280 has a pipe 281 which leads to aresiduum storage tank (not shown) and upon the upper end of which isassembled in the following order, a T iittingi282,ia pipe 283, a Tfitting 284 and a pipe 285 which'is shown in Figs. 2 and 3 asvbrokenoil.' In the'portion of the fractionatingv tower which is shown asbroken away in Fig. 3 the pipe 285 has a T fitting secured theretoandabove this are Joined successively a pipe and a T iitting` for. eachof the tractionating units 54, 55, 56 and`57', the uppermost of thesebeing a pipe 290 and a T fitting 291, the upper end of which issealed'bya plate 292; l

rllhe T fitting `282 connects through a valve 295 and an elbow 296 with'the T fitting 256.

The Tiitting 284 connects through a Valve 297 and an elbow 298 with theT fitting 276. The 'l' iitting 291 connects through a valve 299 andYpermost tractionating unit 57.

Asshown inFig. 4, the outlet pipe 145 of the re-boiler section 181connectsto the lower end of a verticalv pipe: 320 which rises to a levelslightly lower than the top of the battleV condensate run-down pipe 325.`In the same manner condensate run-down lines.324,v326`, 327. 328, 329and 330 are connected-respective# .ly to the re-boiler sections-of theotherfractionatingunits 40, 53, 54, 55, 56 and 57.

As shown in Fig. 1, the-run-down linesf'324, 325, 326, 327 328, 329 and330 pass through the primary heat'exchangers 13 and lead respectivelytoI condensate storage tanks 334, 335, 336, 337, 33s, 33eme 340. Y

As illustrated in section in Fig. 15, a-gas pocketpreventer 344 in theform of a small cylindrical condenser 345is disposedv'erti' cally'abovethe horizontal pipe`321 and has a neck pipe 346 which connects thetwo.

vThe condenser is of the standard` cylindrical 'torni and has `upperand-'lo-werfloors348` and 349 forming upper and lower condens` ingchamhers 350 and 351 and a medial-water chamber 352 through which pipes353 pass, having their ends rolledintosuitableholes in the floors 348`and 349"communicatingbe` tween chambers 350 and 351. Inlet and ut letwater pipes 355 and356 connect with 'the water chamber 352 and areprovided with water vcirculating ineens (notshown) which maintain the`pipes 353 and1 the ,chambers 350 and-351 at a. relatively'lowtemperature: A T fitting 357 communicates through a` nipple 358 with thechamber 35() and through nipples360'y and 361 with check valve 362 and ahand valve 363 respectively. Thecheck valve 362 .permitsy atmosphere tofiow into the chamber 350, Vlmtprevents `an outward iiow therefrom. Thehand valve 363 may be opened to allow gas inthe chamber350-'to escape'to the atmosphere.

As shown in Figs 1, 2,5and6`,each'of the reflux inlet pipesr 107 has aviiowregulating valve 37() which connects to-anipple371 pro- `iectingfrom al refluxmanitold`f372-` Eachof the fraction'atingunitshasa'iseparavtemanifold1372`which'is provided (as that shown inf 1 fortheunit 57 with a supply pipe 375 which' leads to. a pressure pumpv 376l which'has an inlet manifold' 377through which it may draw condensateVfrom any' ofthe ltanks 210 or 334 tof340-inclusive,and supply this for;use as a reflux to 'a particular manifold '372.

The centrifuge 36,A as shown in'Figsf. 13 and-14. has shell 380 ofinverted conicalV forni `and has atangential vapor inleti38'1 providedat the upper end 'thereof anda? ver-V tical central vapor outlet 1pipe383 projecting downwardly through the Vcenter thereolf to within afshortvdistancelo'i the bottoni, from which the liquiddrain pipe 37 leadsthrough aga-s trap'385, back tothe vaperizer 31. VInf the present use'4of the centrifuge 36 a-sep-aration ot entraine'd liquid particlesztromthe vaporleaving thefvapori'zer 3-1 is effected-by thev rapidrotationofthe vapors in the centriiirge-36. Theseparated liquid drainsback I soA intothe vaporizer 3l thro-ugh the pipe 37 and the gas trap385.

on by the apparatus illustrated in Fig. 1 is a continuous process.lvVhen the process is started, vapor is supplied as described i' throughthe vaporline 38 to the lowermost fractionating unit 40 of thefractionating tower 41.V The reiiux valves 3'10 are opened, each ofthepumps 376 is connected 'through its manifold 377 with one ofthecondensate storage tanks, and the pumps 376 are started. Thissupplies the desired grade of condensate as a reflux to each of therefiux manifolds 3.72, from'which it passes through the valves- 370intothe VVreflux inlet pipes 107 and,`passing through the holes 111, fillsthe condensate inlet pipes 94, overflows through the holes 110 and fillseachr condensing pan in the whole towerto a level predetermined by thesetting of the rotors 101 of each of the level controlling Weir valves.The maximum level thus attainable in anyof the condensing pans isvslightly below the top of the riser opening walls 7 8 so that under nocircumstances may liquid in a condensing pan ovcrflowthrough the riservopenings 77. The minimum level attainableby control of the weir valve islocated `slightly above the shelf flange 93.

Thus, after theV operation of the tower is once started and thecondensing pans iilled with refiux totheir minimum level, vapor passingfrom below any given pan to the space above if it must pass up throughthe riser openings 77 into the cavity 84 of the caps 80, downwardlybetween the riser walls 7 8 and the cap walls 82 and 83, out through thenotches 91 underneath the shelf 93 and upwardly atrthe shelfs "1 outered ge Ythrough a layer of liquid reflux.

VIn entering the fractionating tower 41, the vapor mixtureY passes intothe chamber of the fractionating unit 40 and flows upwardly therefromthrough the holes 73 in the distributor plate 72 andis uniformlydistributed over the space 390 above the plate `72.` From the space 390the-vapor passes up through thev condensing panv 75,v as vabovedescribed. A few of the least volatile V1constituent vapors areL therebycondensed from the mixture due @to a slight'drop in temperature in itspassage through the reflux in the pan 7 5. VYAs this condensationcontinues in the pan 7 5 the condensate accumulates and raises the levelof liquid inthe pan so that it overflows through the 'Weir valve 100,passes'V downthevpipe 125 Ythrough the gas trap elbow 121 and into thefand the gasrtrap elbow 122 into the inlet pipe 94 of the condensingpan1l6. Y The level of liquidbeing thus raised `in the panV 116,

an overflow therefrom passes through the.V

weir valve 128, through the elbows 147 and.

146 and the inlet 142 into the re-boiler- 61. Here the mixture of refluxand condensate accumulates until the level is reached, Ywhere Vtheliquid will flow frcinV the vertical pipe 320 along the horizontal pipe321fand downrthe condensate run-down pipe .324 to the storage tank 334.

The portion of the vapor 'mixture which is not condensed in the pan 75passes from the space` 187 thereabove,` up through openings 186, in thebafie' walls 185 in the reboiler 181, to thespace 188., and from there,it passes up successively through the condensr ing pans 1,96 to 191inclusive in the condens@ ing section 180. In each of these pans aportion of the less volatile of the remaining I vapors in the mixture iscondensedby being i slightly cooled in passing through theliquidcontained in the' pan. As the level of liquid rises in each pan due toan accumulation of the condensate, the mixture of `reflux. andcondensate overflows therefrom. This overflow from the pan 191 passesthrough rthe weir 201, the pipe 222 and the elbow 212 into the inletpipe 94 of the pan 192. Traversing the length of the pan 192andthoroughlyV mixing with the liquid therein,this overflow from the pan191 passes ofi" with theover- `flow from the pan 192. In the same mannerthe overflow kfrom thepan 192 passes down to .the pan 193, and theoverflow vfrom `the pan 193 passes to the pan 194, and so on, until theaccumulated overflow from all the con? densing pans 191 to 196 inclusiveis conveyed through the weir 206, the elbows 232 and 231, andthe inlet142, into the re-boiler 181. kThe liquid collects in the re-boiler 181untilit reaches the level from which it` overflows down the run-down*pipel 325 to the storage tank v335. j

The gas pocket preventer 344 Ais provided to condense any vapor whichmay form in anyof the horizontalpipes 321. 'If vapor were allowed tocollect and form a pocket'in a pipe321, this would `stop theV passage ofcondensate into the run-down line connected thereto and, causethecondensate in the reboiler, from which itis the outlet, to over flowinto thecondensing section below.- The check valves 362 are provided topermit access of the ratmosphere toeach pipe321 to prevent sufficientvacuum being kformed therein to start Va siphoning action from anyre-boiler down its run-down line. `The handV valves occurs, no greatinconvenience is occasioned by the necessityY of manually relieving it.V

miV

, The portion of the vapor mixture which l,

units 53, 54, 55, 56 and57. In each of these units the temperature is acertain number of degrees lower than in the next unit below. Thus,vapors of certain liquefying temperatures that will pass through thelower fractionating units, due to the higher temperatures, will uponreaching the first fractionating unit having a temperature below theirliquefying temperature condense and separate out from the vapor mixtureas a condensate.

As these condens-etes collect inthe initial charge of reflux in the.condensing pans, the flow of reflux into the various condensing pans iscidade-wnV by the valves t7()` so that theamount of reflux introducedintoeach pan during the normal operation of .the tower 41 is very smallin proportion to thecondensate 'formed in thatV pan. The effect of theintroduction of reflux is well known in the art and `varies with thegravity Vand boiling point of thereflux. .Specialattentio-n may bedirected, however, to our novel means of thoroughly mixing the reflux ineach` panA condensate inlet pipe 94 with the condensate flowingthereinto from the higher pans in that fractionatingzunit. This equaldistribution is highly important to ythe uniform treatment ofallportions offthe .condensate and reflux mixture as it flows througheach pan and uniformity in the product depends largely upon thisuniformity of action upon all parts of the condensate flowing througheach of the pans.

. The general purpose of the condensing sections, therefore, is tofractionally condense in a .succession of cooling stages the vapors ofsuccessively lower liquefying temperatures contained in the vapormixture entering the tower. "This condensation successively of certaingroups of vapors fromthe vapor mixture, each of which groups has lowerlique- .fying temperatures than the other vapors remaining in the vapormixture, is not ideally attainable by control of the temperature ot thepans of condensate alone. rThis is due to absorption by the condensateof some of the vapors whichnormally liquefy only -at a lower temperaturethan that of the condensate. The vapors thus absorbed in a givencondensing section which are lighter than desired in the product fromthat section must be driven 0E. This is accomplished by heating thecondensate to boiling temperature in the reboiler section immediatelybelow each condensing section by the circulation ot residuum through thepipes 149. Driven oil by the boiling of the condensate, these lightervapors again pass up through the condensing section in which they werelirst absorbed, and whileA a small part of them is re-absorbed a largeproportion escapes on up to the next higher fractionating unit andcontinues on up in this manner' until it isfcondensed in the unit in theproduct of which it belongs.V The residirun is acconiplishedY by bulk ofthe condensate which passesinto each re-boiler consists of thefproductdesired to be tractionally condensed in thatunit. Some of this prod-uctis vaporired in-A the boiling and .driven offy with the lighter absorbedvapers, but this product is all re-condensedin the condensing sectionabove and returned to the re-boiler. The condensate enters the reboilerat'the corner 140, as shownfin Fig. 10,

and ows serially through the five `aisles 15,1

The temperatures of the fractionating .units progressively decrease fromthe bottom to the top of the tower. This reduction in temperature iscontrolled inthe condensing pans-by the temperature and grade ot refluxadmitted and by the depth of liquid maintained in each an. lnthere-boilers the temperature is controlled by the amount of hotresiduum allowed to flow throughthe heat exchange pipes 149 and by theintroduction of a greater or less amount of live steam through theperforated Apipes 166, shown in F igs.'10, `11 and 12. Y The pipingdescribed as connectingthe supply residuuml pipe 22GandV the returnresiduum pipe 280 with the ire-boilers is arranged tol provide forpassing the residuum from 4the pipe226a through the re-boilers either inparallel or in series to the return g pipe `280. :This isf-a greatadvantage in that certain cr'udes may be suitably refined inourfractionating tower when the temperatures of the re-boilers decreaseprogressively from the bottoni re-boiler tothe top re-boiler, Idue' n tothe progressive cooling of residuumpassed serially through there-boilers one atterthe other, from the bottomunit on up to the rtopunit where it is discharged to the return line.

As showny in IFig. 3, the series flow Tof A K cl sing the valves 231,234, 237 and so forth on up to the topmost vvalve (not shown) ot theresiduum supply pipev 226, which topmost valve is always keptclosedduring normal operation.

Also the valves 295, 297 and all similar valves communicating between.the` residuum return line 280 and theire-boilers,l exceptingthentop#most valve 1299.. are closed. The valves 241, 247, 262, 255, 275 and allVsimilar valves, on the fractionating units which "are vbroken away,are` opened. I J

` The yresiduum valve 221 is then opened and.V the pump 22() started.Y`Residuum 4jflows through the pipe 2258#` to the 'T ittin`g230a andthrough the pipe 24()1 the valve. 241 and the elbow 242 to the intakeheader box 155 of the re-bo-iler 61. The residuum flows through thetubes 149 of the re-boiler 61 to theoutlet header-156,'from which itpasses through the T itting 256, the valve 255, the

pipe 254, the elbow v253, the pipe 252, the elf bow 251, the pipe 250,the litting 233, vthe pipe 245, the elbow 246 and the valve 247 into theinlet header 248 of there-boiler 181. The residuum Hows through thetubes 149 of the re-boiler 181 to the outlet header 249 and thencethrough the T fitting 276, the valve Y `2175, the pipe 274,-theelbow'273, the pipe 272, the yelbow 271, the pipe270, the fitting236,-the pipe 260, the elbow 261 and the valve 262 to the header box263. From here the residuum passes through the re-boiler 264 andfromthere serially throughthe upper re-boilers in the same manner as it hasjust 'been described as passing through the rel boilers 61,.V 181 andl264. After Vflowing through the re-boiler 311 of the vuppermostfractionating unit 57, the residuum passes intov'the outletl header box310 and is con veyed from this through the fitting 300, and

' the valve 299 Ato the top Vfitting 291 of the fuum storage pipe 34.-

residuum return line 280. l cooled residuum passes through the line 280to the pipe 281, which empties into the resid- Y When itis possible toroute the residuum thus in series through the re-boilers from the bottomto the top of the tower, a maximum eiiiciency in the extraction of theheat from the hot residuum is accomplished. This is a great advantage inthat only va small quantity of residuum need be diverted from `thesecondary crude oil heat exchangers 15 `for'heating the re-boilers inthe tower. How'- ever, the temperature Yofeach successive re- Vboilerthrough which the residuum flows in series is dependent upon thetemperature to which the residuum has been reduced inthe re-boilerspreviously passed through. rVhen there-boiler temperatures thus at- Y.tained are not suitable for the proper fractopmost of these valves 299which merely re- Y. 50- i i mains open; Y Y f,

Thel hot residuum then passes up the supply pipe 226Tand-outthrough thepipes 240,

v245, 260 and similar pipes for Athe re-boilers,

not `shown in detail. These pipes connect respectively through thevalves 241;, 247 2.627, et

From `here the cetera, with the residuum intake headers 155,

248, 263, et cetera. From the header 155 the residuum l'lows through the11e-boiler 61 and out from the outlet header 156, through the fittings256 and 296', and the valve 295, to the residuum return line 280. Fromthe header 248 residuum passes through the Vre-boiler 181, the header249, theflittings 27 6 and 298,

and the valve 297, to the return residuum line 280. In the same mannerVresiduum passes from the supply line 226l in parallel through all there-boilers tothe return line 280.

Intheparallelroutingof residuum through Y the re-boilers the temperatureofeach reboiler is controlled' by thel'amount of resi duum allowed topass through the re-boiler.- Means for this control are' provided in thevalves 241,247,262, et cetera.

In case a large volume ofV hot residuum were desired to be passedthrough two-orv more of the lower re-boilers, thesevmight be connectedtogether inseries and the re-boilers thereabove in parallels` It willthus be seen that we have produced i a single fractionating tower bywhichia mixture of hydrocarbon. vapors may be fractionally condensedinto several commercial products, each comprising'a certain adjacentgroup of thehydrocarbons contained in the l vapor mixture. This resultcan only be accomplishedbyl our exact temperature control means. u

Another very importantresult of our accomplishing the complete fractionating process in a single tower, combined with our novel residuumcircuitwhich utilizes the heat of the hot residuum to almost 100'percenteliiciency, is thejmarked economy of operatinga relining apparatusin which our fractionating tower is used. In our operation of such aplant, the A L Y iuel consumed has beenas low as 1. (5 per cent of thecrude treated and hasaveraged under 2 per cent over a period of twomonths opera.

tion vhandling various grades of crude. oil.

VThe very best performance previously 'recorded by the largest and mostVprogressive oil companies in relinery practice is a consumpl tion offuel equal to 2.25 per cent of the oil treated. i

In addition to this revolutionary Veconomy of operation of ourViractionating tower is the accuracy of control of theA 'deplilegmatingaction in the various ractionating units which permits cuts tobemadefrom the va-V por mixture, the initialboiling point of each il of whichis higher than the end point for the next lighter cut. This controleliminates the cost of redlstllhng cuts having wrong yinitial or endboiling points Vwhich, .as wellVV vknown, has been heretoiore'an almostcomkmon Vpractice in, thepetroleum'refining in'- dustry. Y

l/Vhat we claim is:

l V.1. In a dephlegmator the combination of: Y walls formingfa verticalclosed chamber;

ilo

means for passing a vapor mixture into the bottom of said chamber; meansfor conducting a vapor mixture from the top of said chamber; floorplates secured to said walls to` form a series of dephlegmating pansdisposed one over the other; walls forming risersin said floor plates;caps disposed over the upper ends ot said risers so that the mouthsthereof are disposed on a level between the top from said lowermost pan.

2. In a fractionating tower, the combination of: a plurality of unitsplaced one above stages, each of said units comprising a condensingsection and a re-boilng section disposed immediately under saidcondensing section, each of said condensing sections coinprising aseries of pans having walled riser openings therein and caps placed oversaid riser openings and adapted to deflect vapors rising through saidopenings downwardly into said pans, and each of said re-boiling sectionscomprising an open boiler having walled riser openings therein; means:tork conducting condensate from the lowermost pan of each condensingsection to its re-boilers; means for conducting condensate from each ofthe other pans tothe one immediately beneath it; and means fordetermining the level above which condensate is drawn from each of thepans.

3. In a fractionating tower, the combination of: a plurality of unitsplaced one above the other providing a series of ractionating stages,each of said units comprising a condensing section and a reboilingsection disposed immediately under said condensing section, each of saidcondensing sections comprising a series of pans having walled riseropenings therein and caps placed over said riser openings and adapted todeflect vapors rising through said openings downwardly into said pans,and each of said re-boiling sections comprising an open boiler havingwalled riser openings therein; a heat exchange element in each re-boilersection; la supply pipe for supplying hot residuum to said heat ex.

change elements; a return pipe; and means connecting said heat exchangeelements with said supply and return pipes whereby the residuum may berun from the supply pipe through said heat exchange elements inparsupply pipe through said heat exchange elements in series to thereturn pipe. v

4. A combination asset forth in claim 3 in which each re-boiler sectionhas a run-down i line; an inverted U-shaped pipe connecting of saidlevels from` which condensate isV drawn; and means for drawingcondensate the other providing a series of fractionatingv allel relationto the return pipe or from the the upper end of 'each run-down line withtheV lowerportion of itsrespective re-boiler; and meansfor condensingany Vapor POGket which mayforrn in said U-shaped pipe. Y

551Av combination as set forth in claim 2 inf which means are providedfor-supplyingsteani directlyto the condensatein each reboiler section. Yp Y 6. A combination-as defined in claim 2 to which isA addedfineans forintroducing a ref i 751 flux liquid into the condensateand thoroughlymixing the Vreilux with said condensate where the condensatel isdischarged insaid pans. f i Y g '7, ln a fractionating tower, thecombination ots: a plurality of units placed o-ne above the otherprovidinga series of fractionating stages, each of said units comprisinga con-f densing section and a re-boilingsection disposed immediatelyunder said condensing; section, each of said `condensing sectionsCoin-LA prising'a series of pans having walled riser openings thereinand' caps disposed over said riser openings adapted to deflect vaporsrising through said openings downwardly into said pans, each of saidre-boiling sections comprising an open boiler having walled riseropenings therein, and a run-downl line; a pipe connecting the upper endof each run-down line with the lower portion of its respectivere-boiler; a heat exchangeelement in each re-boiler section; a supplypipefor supplying hot residuum to said heat exchangefelements; a returnpipe; a check valve provided to communicate between said irst mentionedpipe and the atmosphere; and means con? necting said heat exchangeelements with said f supply and return pipes and adapted to run theresiduum through said heat exchange elements in parallel relation tothereturn pipe 1'0'5 or-A through said heat exchange elementsV in seriestothe return pipe. Y y

'8.In a fractionating tower, the combination oie: a plurality of unitsplaced one above the other providing series of fractionating' 110stages, each of said units comprising a condensing section and are-boiling section disposed immediately under said condensing section,each of said condensing sections come prising a series of pans havingwalled riser 115,

openings and caps disposed over said openings adapted to deliect vaporsrising through said openings downwardly: into I said pans, cachot saidre-boiling sections comprising 'an Y open boiler having walled riser`openings therein; a heat exchange element in each ref boiler section; Vasupply pipe for supplying hot residuum to said heat exchange elements;

la return pipe; and means `for runningthe residuum from the supply pipethrough said heat exchange elements in'parallel relation to the returnpipe or through 'said heatV exchange elements in series to the returnpipe.

. 9. A combination as setrforth in claim V8 including: a run-down linefor each re-boiler section; a pipe connecting the upper end of Yeachrun-down line with the lower portion of its respective boiler; and meansfor-con- (lensing vapor which may form in a, pocketV 5in said pipeconnecting the run-down line With'its respective re-boiler. Y

' 10. A Combination as set forth in claim 8 in Whicheach re-boilersection has a rundown lineV and an inverted Ueshaped pipe m connectingeach run-down line with its respecti-vefre-boiler.

11.'.A combination as setforth in claim 7 in which said? Vlirstmentioned pipe is U- shaped. f 153 12. A combination as set forth inyclaim 7 in which means is providedfor condensing vapor Which may formin a pocket insaid first mentioned pipe.- f

In testimony whereof, we have hereunto 205 set our hands at Los'Angeles,California, this 24th day of December, 1925.v

FRANK A.. MILLIFF.

JOHN A. MILLIFF.

